By looking at the different body structures of an animal, it is possible to get information about how an animal lives. A shape, foot, bill, jaw, and tooth can all be clues to an animal's life-style. For example, it is reasonable to assume — by looking at its long neck — that the plant-eating giraffe eats leaves high in trees.

ShapeWhales and fish are totally different types of creatures. However, the body of a typical fish has the same streamlined and torpedo-shaped body as that of a whale. Their similar shapes are both adaptations to living in the water. With a streamlined shape, an animal can move through water with less effort. The pointed head of a water animal, such as a fish, wedges water aside. The long, slender body glides behind, almost as if it is following through a "hole" in the water made by the head.

Other fish, such as the stingray, have flattened bodies that resemble a pancake. Even though their bodies are not torpedo-shaped, they are streamlined in another way. A stingray's body can grow to about 5 feet (1.5 meters) wide. However, from the top surface of its body to the bottom, it is only a few inches deep.

Another fish, the moray eel, has a long, slender, snakelike body. Its shape allows it to slither into crevices and holes in reefs after the octopuses and crabs that are its prey. Water animals are not the only animals that need flexible, streamlined bodies. The weasel, a land animal, also has a snakelike body. Its slender, flexible body enables it to snake through underground burrows to catch the rabbits and rodents it feeds on.

Feet and LegsThe feet of some birds have powerful toes tipped with sharp, hooked claws, or talons. Talons are characteristic of birds that hunt, such as eagles and hawks. With the talons, the hunter bird seizes its prey. Once it has the victim within its grasp, the talons automatically tighten to hold the victim fast.

The favored diet of birds of prey varies greatly. The red-tailed hawk catches rodents, ground birds (such as pheasants), lizards, and snakes with its strong talons. The bald eagle feeds largely on fish that are caught near the surface of the water.

The curved, sharp claws of cats are used in much the same manner to grab and hold prey. However, the cat has an additional feature important to a land animal: It can withdraw, or retract, its claws into sheaths within the toes. This protects the claws when they are not needed to grasp prey. Withdrawing its claws also allows the cat to step softly when stalking its prey. Cats — from lions to house cats — creep up as close as they can to their prey before they pounce on it with a final rush.

One cat is an exception — the cheetah. It has blunt claws, similar to a dog's, that it cannot withdraw. It also hunts more like such members of the dog family as wolves and African wild dogs than a cat. The cheetah does not quietly stalk its prey before pouncing and grabbing with its claws; rather, the cheetah runs down its prey, knocking it to the ground, and with its strong jaws grabs the throat of its victim and suffocates it.

The lynx, a cat that lives in the cold coniferous forest, has large, broad feet. As the lynx travels over the snow in search of prey, its feet act like snowshoes, keeping the cat from sinking into the snow. The spider monkey and the gibbon have unusually long fingers and toes, which they hook over branches as they swing through the trees.

Jaws and TeethBecause animals have different ways of feeding, the body structures used for eating are different — even within the same family of animals. All birds use their beaks, or bills, to obtain food; however, among birds, there are many different kinds of bills. The woodpecker uses its chisel-like bill to chip away the bark and wood from trees and get to the insects hiding underneath. The pine grosbeak uses its short, heavy bill to crush seeds. The heron uses its long, spearlike bill to grab fish and frogs.

The spotted hyena hunts other animals, but it also feeds off the remains of animals killed by other predators, such as lions. With its large, powerful jaw muscles, the hyena is able to carry off and eat the bones and other remains that most animal jaws cannot crack.

A fish with strong jaws and heavy, wide teeth is the parrot fish. Similar to the hyena, the parrot fish uses its jaws for crushing. Found in the warm waters surrounding coral reefs, the parrot fish crushes the rock-hard coral to feed on the small, soft animals that secrete it.

The teeth and jaws of animals that eat plants are different from those of animals that eat other animals. Plant-eating animals, such as horses, generally have broad, flat-edged teeth for chewing leaves and grass; meat-eating animals, such as dogs, have long, sharp teeth for tearing and chewing flesh.